32.2.2 Checking routes to IPv6 multicast group addresses

When IPv6 multicast routing information has been set on the Switch, use the show ipv6 mcache and show netstat multicast commands to check whether routes to the destination addresses exist. If it does not exist, and outgoing is incorrect, check for "32.2.3 IPv6 PIM-SM info" and "Check 32.2.4 MLD info".

The show ipv6 mcache command displays the IPv6 multicast forwarding entries retained in the IPv6 multicast routing program. The show netstat multicast command displays the IPv6 multicast forwarding entries registered in hardware.

Note that the show netstat multicast command also displays the negative cache (packet discarding entry for which no output interface exists).

Figure 32-7: Result of executing show ipv6 mcache command
> show ipv6 mcache Date 20XX/04/20 15:20:00 UTC Total: 1 route - Forwarding entry ---------------------------------------------------------- Group Address Source Address ff15::2 2001:db8::100 uptime: 00:20 expires: 02:40 flags: incoming: VLAN0002 outgoing: VLAN0001 VLAN0003 >

Figure 32-7: Result of executing show ipv6 mcache command

> show ipv6 mcache
Date 20XX/04/20 15:20:00 UTC
Total: 1 route
- Forwarding entry  ----------------------------------------------------------
Group Address                            Source Address
ff15::2                                  2001:db8::100
    uptime: 00:20    expires: 02:40    flags:
    incoming:
        VLAN0002
    outgoing:
        VLAN0001
        VLAN0003
>

Figure 32-8: Result of executing show netstat multicast command
> show netstat multicast Date 20XX/04/10 15:20:00 UTC Virtual Interface Table is empty Multicast Forwarding Cache is empty IPv6 Virtual Interface Table Mif Rate PhyIF Pkts-In Pkts-Out 0 0 VLAN0004 0 0 1 0 VLAN0002 0 0 2 0 VLAN0001 0 0 3 0 VLAN0003 0 0 IPv6 Multicast Forwarding Cache Origin Group Packets Waits In-Mif Out-Mifs 2001:db8::100 ff15::2 0 0 1 2 3 Total no. of entries in cache: 1 >

Figure 32-8: Result of executing show netstat multicast command

> show netstat multicast
Date 20XX/04/10 15:20:00 UTC
Virtual Interface Table is empty
 
Multicast Forwarding Cache is empty
 
IPv6 Virtual Interface Table
 Mif   Rate      PhyIF         Pkts-In   Pkts-Out
   0      0   VLAN0004               0          0
   1      0   VLAN0002               0          0
   2      0   VLAN0001               0          0
   3      0   VLAN0003               0          0
 
IPv6 Multicast Forwarding Cache
 Origin                 Group           Packets Waits In-Mif Out-Mifs
 2001:db8::100          ff15::2               0     0    1    2  3
 
Total no. of entries in cache: 1
>

[Figure Data]